11,312 research outputs found
Virtual Machine Support for Many-Core Architectures: Decoupling Abstract from Concrete Concurrency Models
The upcoming many-core architectures require software developers to exploit
concurrency to utilize available computational power. Today's high-level
language virtual machines (VMs), which are a cornerstone of software
development, do not provide sufficient abstraction for concurrency concepts. We
analyze concrete and abstract concurrency models and identify the challenges
they impose for VMs. To provide sufficient concurrency support in VMs, we
propose to integrate concurrency operations into VM instruction sets.
Since there will always be VMs optimized for special purposes, our goal is to
develop a methodology to design instruction sets with concurrency support.
Therefore, we also propose a list of trade-offs that have to be investigated to
advise the design of such instruction sets.
As a first experiment, we implemented one instruction set extension for
shared memory and one for non-shared memory concurrency. From our experimental
results, we derived a list of requirements for a full-grown experimental
environment for further research
Using Java for distributed computing in the Gaia satellite data processing
In recent years Java has matured to a stable easy-to-use language with the
flexibility of an interpreter (for reflection etc.) but the performance and
type checking of a compiled language. When we started using Java for
astronomical applications around 1999 they were the first of their kind in
astronomy. Now a great deal of astronomy software is written in Java as are
many business applications.
We discuss the current environment and trends concerning the language and
present an actual example of scientific use of Java for high-performance
distributed computing: ESA's mission Gaia. The Gaia scanning satellite will
perform a galactic census of about 1000 million objects in our galaxy. The Gaia
community has chosen to write its processing software in Java. We explore the
manifold reasons for choosing Java for this large science collaboration.
Gaia processing is numerically complex but highly distributable, some parts
being embarrassingly parallel. We describe the Gaia processing architecture and
its realisation in Java. We delve into the astrometric solution which is the
most advanced and most complex part of the processing. The Gaia simulator is
also written in Java and is the most mature code in the system. This has been
successfully running since about 2005 on the supercomputer "Marenostrum" in
Barcelona. We relate experiences of using Java on a large shared machine.
Finally we discuss Java, including some of its problems, for scientific
computing.Comment: Experimental Astronomy, August 201
Hard real-time Java virtual machine for Space applications
International audienceThe AERO ($UFKLWHFWXUH IRU (QKDQFHG 5HSURJUDPPDELOLW\ DQG 2SHUDELOLW\) is an ESA project with the objectives to investigate on a real-time Java virtual machine for ERC32 processor. Special attention was put on the garbage collection mechanism and deterministic execution model. The project have first investigate existing virtual machine to choose a potential candidate that will be customized, are then investigates the definition of requirements concerning a real-time interpreter in on-board systems. The second phase of the project was dedicated to the definition of software functions of the real-time Java virtual machine and to their implementation and assessment through validation tests. The resulting application is the AERO-JVM
The Garbage in the Public Space: Sensitization by Science Teaching Using Virtual Reality
This paper recounts the experience of a teaching project, entitled "Virtual Reality in Science Teaching", which aimed to support future science teachers to plan actions addressing the issue of garbage in public spaces from a context, and the use of technologies, with a view to strengthening citizenship and public health. Initially, we contextualize the problem in the garbage in the public spaces from theorists and data that demonstrate the real situation of the world and the city of Manaus. Then it was presented how virtual reality can help educators in the teaching-learning process in the face of the technological environment that is being established in education. Through the use of Google form, we check the development of the students on the subject. According to the students themselves, the tool proposed here has the ability to transport the person to the middle of the problem, causing real awareness and change of attitude
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